Showing the decreasing cooldown on a passive skill

[bugbear]

How would I go about making a passive spell that, when triggered to go on cooldown, shows the passive skill's cooldown decreasing (like reincarnation). I thought I had bookmarked something explaining this a while ago but cant seem to find it.

 

[bugbear]

bumping

 

[Naga'sShadow]

I belive that is done by hiding the skill that's in cooldown, and then adding a dummy ability that looks the same. Except the dummy is an active spell that is immediately ordered to cast and does nothing. Then you get the cooldown effect. When the cooldown is done you remove the active ability and unhide the passive, note that while this should work with reincarnation I don't know how it would effect a passive like an aura since the only way I know to hide something is with disable ability for player.